Main mechanisms controlling mRNA concentrations.

vs. indicates the growth conditions considered for the calculation of the regulation coefficients. Chemostat and batch indicate that RNA half-lives were determined in continuous or discontinuous cultures, respectively. In chemostat cultures, cells were at a steady state, with growth limited by the isoleucine concentrations. In batch cultures, isoleucine in the medium was progressively consumed (until starvation was reached) and the cells were in a dynamic process of adaptation.